The invention relates to machines for brewing coffee, tea or other hot beverages, and more particularly to improvements in machines of the type wherein the housing embodies or carries a container for cold liquid and the housing further contains or carries an electric liquid heating device serving to raise the temperature of liquid before the thus heated liquid comes into contact with comminuted coffee beans, tea leaves, pulverulent chocolate or another flavoring agent. Still more particularly, the invention relates to improvements in brewing machines of the type known as "Brewmaster" which are distributed by the assignee of the present application.
Commonly owned U.S. Pat. No. 4,790,240 granted Dec. 13, 1988 to Henn et al. for "Machine for brewing hot beverages" discloses a machine wherein heated liquid is caused to flow through a riser on its way into a filter holder in which the conveyed liquid comes into contact with the flavoring agent. It is desirable to ensure that the filter holder receive heated liquid at a substantially constant rate. Attempts to guarantee delivery of heated liquid at a substantially constant rate include the provision of a collecting receptacle above the filter holder. Heated liquid which ascends in the riser is caused to enter the receptacle, and the latter has an outlet which discharges heated liquid, at a desired rate, into the filter holder. The outlet is normally located substantially above the central portion of the filter holder. Problems arise when the riser conveys heated liquid (normally water) as well as steam. Therefore, many conventional brewing machines are provided with additional outlets which discharge steam into the surrounding atmosphere.
In accordance with a presently known proposal, the collecting receptacle for heated liquid comprises a cylindrical sidewall which extends upwardly from a bottom wall to define a chamber for heated liquid. The chamber is open at the top, and the cylindrical sidewall has an inlet which is located diametrically opposite the outlet for heated liquid. The bottom wall is provided with a slightly curved liquid-deflecting baffle which is adjacent the outlet and against which the liquid must flow on its way toward and into the outlet. The receptacle is further provided with an upright cylindrical steam evacuating tube which extends through the bottom wall. The upper end of the tube receives steam from the chamber within the cylindrical sidewall, and the lower end of the tube discharges steam into the filter holder in such a way that steam is compelled to flow vertically downwardly. The tube is spaced apart from the aforementioned liquid deflecting baffle at the outlet for heated liquid.
The just discussed machine exhibits a number of drawbacks. Thus, the baffle causes pronounced turbulence as a result of direct impingement of inflowing liquid against its deflecting surface. The inflowing liquid is caused to flow substantially at right angles to and against the deflecting surface. The thus deflected or reoriented stream of heated liquid can flow around the baffle on its way toward and into the outlet for heated liquid. A small portion of inflowing liquid can bypass the baffle and flows directly toward the outlet. The resulting currents of heated liquid in the chamber cause the aforementioned turbulence. Secondly, the vertical tube directs steam toward the lid of the filter holder or, if the lid is not in place, directly against the supply of flavoring agent in the filter holder. This creates problems if the flavoring agent consists of or contains finely comminuted coffee beans.